The invention relates generally to remotely actuated rearview mirrors for motor vehicles, and more particularly, to an electrically actuated outside rearview mirror for motor vehicles which is universally adjustable with separate motions about two oblique, co-planar axes.
Electrically actuated outside rearview mirrors for motor vehicles are known in the prior art. These mirrors are remotely operable from the interior of the vehicle by appropriate actuating switches or the like. In many cases, these mechanisms only provide for the pivotal movement of the mirror or mirrors about the vertical axis. Such electrically actuated rearview mirrors adjustable about a vertical axis are frequently found on trucks, buses, tractor trailers and the like.
Electrically actuated outside rearview mirrors and similarly related devices which are adapted to be pivoted about a pair of non-colinear or orthogonal axes, such as a horizontal and vertical axis, are of coursee more complex and costly. This added cost and complexity is a factor that has led to the popularity of mechanical cable actuated remote control rearview mirrors in the automotive field. The electrical actuation of outside rearview mirrors is more difficult because of the requirement of pivoting the mirrors about mutually orthogonal axes. This dictates the use of two separate electrical drive mechanisms which are operable independently of each other. Even though relatively small electrical motors are available, there are obvious difficulties in packaging the motor and associated drive train within the mirror housing in a manner that withstands extreme temperatures, vibration, shock loading, moisture, salt and other road chemicals. Road vibration is a particularly acute problem with several prior art designs since these designs allow the mirror to flutter at certain vibration frequencies encountered during normal road travel, thus blurring the mirror image and substantially reducing the effectiveness of the mirror. Moreover, these prior art designs do not provide for accuracy of operation in that the operating clearances apparently required by the design of their drive means and the mode of coupling the same with the mirror are such that the mirror is subject to uncontrolled multi-directional pivotal movements or "drift", as opposed to accurately controlled single-directional pivotal movement, when either of its drive means is independently operated, as for instance when an operator desired to achieve only vertical or horizontal adjusting movements of the mirror.
A further problem associated with many prior art electrically actuated rearview mirrors is a lack of adjustability in the event of a power failure. Power failures are not uncommon in these mirrors because of the aforementioned design problems, as well as other problems associated with these mirrors and their power supplies. This lack of adjustability can cause a dangerous set of circumstances wherein the mirror has little or no utility to the operator because of its lack of adjustability to accommodate operators with varying heights and seating positions.